Culture of microalgae Chlorella minutissima for biodiesel feedstock production.

Microalgae are among the most promising of non-food based biomass fuel feedstock alternatives. Algal biofuels production is challenged by limited oil content, growth rate, and economical cultivation. To develop the optimum cultivation conditions for increasing biofuels feedstock production, the effect of light source, light intensity, photoperiod, and nitrogen starvation on the growth rate, cell density, and lipid content of Chlorella minutissima were studied. The fatty acid content and composition of Chlorella minutissima were also investigated under the above conditions. Fluorescent lights were more effective than red or white light-emitting diodes for algal growth. Increasing light intensity resulted in more rapid algal growth, while increasing the period of light also significantly increased biomass productivity. Our results showed that the lipid and triacylglycerol content were increased under N starvation conditions. Thus, a two-phase strategy with an initial nutrient-sufficient reactor followed by a nutrient deprivation strategy could likely balance the desire for rapid and high biomass generation (124 mg/L) with a high oil content (50%) of Chlorella minutissima to maximize the total amount of oil produced for biodiesel production. Moreover, methyl palmitate (C16:0), methyl oleate (C18:1), methyl linoleate (C18:2), and methyl linolenate (C18:3) are the major components of Chlorella minutissima derived FAME, and choice of light source, intensity, and N starvation impacted the FAME composition of Chlorella minutissima. The optimized cultivation conditions resulted in higher growth rate, cell density, and oil content, making Chlorella minutissima a potentially suitable organism for biodiesel feedstock production.

Tang H ，Chen M ，Garcia ME ，Abunasser N ，Ng KY ，Salley SO ... -  《-》

Effects of various abiotic factors on biomass growth and lipid yield of Chlorella minutissima for sustainable biodiesel production.

Chandra R ，Amit ，Ghosh UK 《-》

Optimization of the biomass production of oil algae Chlorella minutissima UTEX2341.

High production cost is a major obstacle to the extensive use of microalgae biodiesel. To cut the cost and achieve higher biomass productivity, Chlorella minutissima UTEX2341 was cultured under photoheterotrophic conditions. With the carbon, nitrogen and phosphorus concentration of 26.37, 2.61 and 0.03 g L⁻¹ d⁻¹ respectively, a maximum biomass productivity of 1.78 g L⁻¹ d⁻¹ was obtained, which was 59 times more than that cultured under autotrophic condition. The lipid productivity reached 0.29 g L⁻¹ d⁻¹, which was 11.9 times higher than the highest value reported by Oh et al. (2010). The conversion rate of microalgae lipids to FAME was found to be elevated from 45.65% to 62.97% and the FAME productivity increased from 1.16 to 180.68 mg L⁻¹ d⁻¹ after the optimization. 94% of the fatty acid of C. minutissima UTEX2341 was found to be composed of palmitic, oleic, linoleic and γ linoleic and the unsaturated fatty acids were the main parts (79.42%).

Li Z ，Yuan H ，Yang J ，Li B ... -  《-》

Improvement of lipid content of Chlorella minutissima MCC 5 for biodiesel production.

Lipids extracted from microalgae have been considered as a potential source for the production of biodiesel. Enhancement of lipid has the limitations of low biomass productivity. So, the main objective of the present study was to deduce suitable conditions for the improvement of biomass production followed by enhancement of lipid content. After optimization, a strategy for two stage cultivation was utilized where high lipid content was obtained with a high biomass concentration. Optimization of biomass production of Chlorella minutissima MCC 5 was carried out under different intensities of light, temperatures, concentrations of nitrate and phosphate using Taguchi model. A suitable synergy of the four parameters yielded maximum biomass (1.93 g L(-1)) in airlift reactor. Temperature was found to be relatively effective than other parameters for higher biomass production. Activation energy for the cell growth was determined (47.95 kJ mol(-1)). Among the various (photo, thermal, nitrate and phosphate) stress conditions studied, nitrate limitation (1 mM) was found to be suitable for the enhancement of lipid resulting highest yield (48.26% w/w). Two stage cultivation of the microalgae yielded a maximum lipid content of 46% w/w with a biomass concentration of 2.2 g L(-1). Additionally, FAME analysis exhibited significant increase of oleic acid in the biodiesel. So, C. minutissima MCC 5 cultivated under nitrate stress could be a possible feedstock for biodiesel production.

Chakraborty S ，Mohanty D ，Ghosh S ，Das D ... -  《-》

Recycled de-Oiled Algal Biomass Extract as a Feedstock for Boosting Biodiesel Production from Chlorella minutissima.

Arora N ，Patel A ，Pruthi PA ，Pruthi V ... -  《-》